Wildbirds & Peacedrums are fast becoming prolific. One could possibly attribute this to their being man and wife, a partnership that clearly affords spending their ample time together productively, as well as perhaps the long dark winters of their native Gothenburg offering little diversion. Whatever, Rivers is the duo's third barely-there long-player in not much over three years. However, it started life as two separate EPs, which explains why the release comes split over two discs.

The ghostly Retina EP was recorded with the 12-piece Schola Cantorum Reykjavik Choir who have previously worked on Björk's Medúlla album. The other, Iris, uses Andreas Werliin's steel-pan percussion as a base, veering off into frosty sleigh rides courtesy of Mariam Wallentin's theatrical quiver.

Retina kicks off with Werliin's minimal percussion set against Wallentin's reverent vocal and the rousing Gregorian contributions of the choir that combine to form an epic, experimental folk. Swelling with Beach House-like glacial melody, "Bleed Like There Was No Other Flood" has its eerie creep added entirely by the choir, as does its less successful successor "Tiny Holes In This World".

The stark beauty of "Under Land And Over Sea" comes on like some sombre midnight mass, which, though stirring, is perhaps not an everyday listen. In comparison, "Fight For Me" is relatively lively and builds into a huge composition of menacing urgency thanks to its watery percussion, Werliin's tom toms and the choir's deepest voices. The first half of Rivers signs off strongly with "Peeling Off The Layers" - a sparse exercise in snares and vocal harmonising that sees Wallentin searching in vain for her preferred octave.

Having split the album into two discs forces a pause between the EPs and the arrival of Werliin's steel pan is thus more pronounced as Iris begins. Those familiar with the band's previous and excellent offering The Snake will find it a welcome return, but also notice an increase in its prominence. Now the steel makes a statement. And it does so immediately, acting as glue, supplying the percussive opener "The Wave" with an otherwise-absent direction.

Recalling fellow Swedes The Knife on some sort of inhibitors, "The Drop" is lucid but languid, whereas "The Course" is altogether faster in tempo. Sounding like melt-water dripping in a spring-like sunshine, it nearly succeeds in overshadowing the best moments of the draftier Retina EP. Wallentin closes Iris in a more whispery mood, the stark sounding theme-completers "The Lake" and "The Well" sweetened with Werliin's ever-present and shimmering steel.

The Retina EP is a resounding success. The depth added by the timeless choir is inspired. The calypso flavours of Iris are more of an acquired taste though it must be said, but to Wallentin and Werliin's credit they never sound contrived and their blending of instrumentation is seamless. More importantly however, together, Rivers is cool and powerful, elegant and utterly convincing.

If it hadn't been for the TV series Fortitude l would not have come across this group. I bought it for the theme song" Peeling off layers"and now have a very interesting album which reminds somewhat of Enigma. If you like this type of haunting music like me you will love it.